I love my LOMO drybag rucksacks. They are reliable yet cheap (£30 UK pounds) drybag rucksacks, waterproof, and confortable. I use mine for commuting by bike, and for all my work.
There's just one irritation with them - the side-straps, which are used to clip the rolled top shut, fall down to the floor when unclipped, meaning you have to rummage around to retrieve them when you want to close the bag again.
What would be nice would be some side-strap holders we could add on, to hold the straps where we want them. But clearly, as this is meant to be a waterproof bag, be want to avoid sewing anything onto it. So we need to glue on some vinyl patches.
This Instructable is a step-by-step guide to modding the LOMO drybag rucksack, but of course the very simple techniques used can be used for all sorts of modding and hacking on any drybag or other outdoor gear design. Choose your fabric and adhesive according to what you're working on and it should work fine.
I did this hack on my original LOMO rucksack 3 years ago, and it lasted well. I always regretted not making an Instructable at the time. I had to replace that original rucksack this year because it was utterly utterly worn out, just normal wear and tear due to what I had put it through over 3 years hard use. So I thought, since I'd have to add the patches again, I'd bash out a quick Instructable of it. I hope it's helpful to someone.
Step 1: Materials
I used some black vinyl which I got from eBay. It was listed as "BLACK Waterproof UV Resistant 560gms PVC Material HEAVY DUTY TARPAULIN Fabric" and it was just what was needed.
I also used some Bison Vinyl Adhesive which is (according to some other Instructables) the best stuff for this kind of thing. It certainly worked well - 3 years ago I did this hack on my original LOMO rucksack and the glue was absolutely fine 3 years later.
Step 2: Cut Out the Patches From the Vinyl Material
I did a simple design in 2D CAD to help anyone else who wants to follow this Instructable, they are attached to the Instructable in both DXF (2D CAD) format, and PDF for ease of printing and reuse.
Using a craft knife and cutting board I cut the shapes out of the vinyl, and cut slots exactly the width of the webbing side-straps, for the side-straps to thread through. I also removed the webbing clips from the end of the side-straps, so that I'd be able to thread the webbing strap through the new patches (we will be putting them on later)
Step 3: Glue the Patches On
I measured where I wanted the patch (in my case 3mm from the seam and 145mm from the bottom corner patch but YMMV) and marked onto the bag where the patch was going to go, so I would be able to apply glue carefully to the bag and the patch accurately.
Be careful not to put any glue on th the back of the 'loop' part in the centre of the patch - you don't want to glue this loop down, that's the whole point of the hack!
I applied and spread Bison Vinyl Adhesive to both pieces, and waited 5 minutes to start the curing process.
Step 4: Allow to Dry, and Thread the Side Straps Through Again
Once the patches are applied the glue dries pretty quickly although the full curing time is 6 hours.
I was able to thread the side-straps through after half an hour or so, and reattach the webbing clips.
Step 5: Finished Article! Side Straps Always Where You Need Them.
Once everything's threaded back together you are finished!
No more grovelling around on the floor for the side straps of your LOMO rucksack!